GM Service Manual Online
For 1990-2009 cars only

Application

Specification

Metric

English

General Data

  • Engine Type

V6

  • Regular Production Option (RPO) Code LF6 VIN Code X, and RPO Code L35 VIN Code W
  • Displacement

4.3L

262 CID

  • Bore

101.60 mm

4.012 in

  • Stroke

88.39 mm

3.480 in

  • Compression Ratio

9.2:1

  • Firing Order

1-6-5-4-3-2

  • Spark Plug Gap

1.52 mm

0.060 in

  • Oil Pressure (Minimum) at Normal Operating Temperature

42 kPa at 1,000 RPM

125 kPa at 2,000 RPM

166 kPa at 4,000 RPM

6 psig at 1,000 RPM

18 psig at 2,000 RPM

24 psig at 4,000 RPM

Balance Shaft

  • Rear Bearing Journal Clearance

0.050-0.088 mm

0.0020-0.0035 in

  • Rear Bearing Journal Diameter

38.085-38.100 mm

1.4994-1.500 in

Camshaft

  • End Play

0.0254-0.2286 mm

0.0010-0.0090 in

  • Journal Diameter

47.440-47.490 mm

1.8677-1.8696 in

  • Journal Diameter Out-of-Round

0.025 mm (Maximum)

0.0010 in (Maximum)

  • Lobe Lift (Exhaust) (L35)

7.20-7.30 mm

0.283-0.287 in

  • Lobe Lift (Exhaust) (LF6)

6.54-6.64 mm

0.257-0.261 in

  • Lobe Lift (Intake) (L35)

6.97-7.07 mm

0.274-0.278 in

  • Lobe Lift (Intake) (LF6)

6.76-6.86 mm

0.266-0.270 in

  • Runout

0.065 mm

0.0026 in

Connecting Rod

  • Connecting Rod Bearing Clearance (Production)

0.038-0.078 mm

0.0015-0.0031 in

  • Connecting Rod Bearing Clearance (Service)

0.025-0.076 mm

0.0010-0.0030 in

  • Connecting Rod Side Clearance

0.15-0.44 mm

0.006-0.017 in

  • Connecting Rod Journal Diameter

57.116-57.148 mm

2.2487-2.2497 in

  • Connecting Rod Journal Taper (Production)

0.00508 mm (Maximum)

0.00030 in (Maximum)

  • Connecting Rod Journal Taper (Service)

0.025 mm (Maximum)

0.0010 in (Maximum)

  • Connecting Rod Journal Out-of-Round (Production)

0.007 mm (Maximum)

0.0002 in (Maximum)

  • Connecting Rod Journal Out-of-Round (Service)

0.025 mm (Maximum)

0.0010 in (Maximum)

Crankshaft

  • Crankshaft Bearing Clearance (Journal #1-Production)

0.02-0.508 mm

0.0008-0.0020 in

  • Crankshaft Bearing Clearance (Journal #2, #3, and #4-Production)

0.028-0.058 mm

0.0011-0.0023 in

  • Crankshaft Bearing Clearance (Journal #1-Service)

0.0254-0.05 mm

0.0010-0.0020 in

  • Crankshaft Bearing Clearance (Journal #2, #3, and #4-Service)

0.025-0.063 mm

0.0010-0.0250 in

  • Crankshaft End Play

0.050-0.20 mm

0.002-0.008 in

  • Crankshaft Journal Diameter (Journal #1)

62.199-62.217 mm

2.4488-2.4495 in

  • Crankshaft Journal Diameter (Journal #2 and #3)

62.191-62.215 mm

2.4485-2.4494 in

  • Crankshaft Journal Diameter (Journal #4)

62.179-62.203 mm

2.4480-2.4489 in

  • Crankshaft Journal Out-of-Round (Production)

0.005 mm (Maximum)

0.0002 in (Maximum)

  • Crankshaft Journal Out-of-Round (Service)

0.025 mm (Maximum)

0.0010 in (Maximum)

  • Crankshaft Journal Taper (Production)

0.007 mm (Maximum)

0.0003 in (Maximum)

  • Crankshaft Runout

0.025 mm (Maximum)

0.0010 in (Maximum)

Cylinder Bore

  • Diameter

101.618-101.643 mm

4.0007-4.0017 in

  • Out-of-Round (Production)

0.0127 mm (Maximum)

0.00050 in (Maximum)

  • Out-of-Round (Service)

0.05 mm (Maximum)

0.002 in (Maximum)

  • Taper (Production Relief Side)

0.025 mm (Maximum)

0.0010 in (Maximum)

  • Taper (Production Thrust Side)

0.012 mm (Maximum)

0.0005 in (Maximum)

  • Taper (Service)

0.025 mm (Maximum)

0.0010 in (Maximum)

Cylinder Head

  • Surface Flatness

0.10 mm (Maximum)

0.004 in (Maximum)

Exhaust Manifold

  • Surface Flatness

0.05 mm (Maximum)

0.002 in (Maximum)

Intake Manifold

  • Surface Flatness

0.10 mm (Maximum)

0.004 in (Maximum)

Oil Pan

  • Oil Pan Alignment at Rear of Engine Block

0.3 mm (Maximum)

0.011 in (Maximum)

Piston

  • Piston Bore Clearance (Production)

0.018-0.061 mm

0.0007-0.0024 in

  • Piston Bore Clearance (Service)

0.075 mm (Maximum)

0.0029 mm (Maximum)

Piston Pin

  • Clearance in Piston (Production)

0.013-0.023 mm

0.0005-0.0009 in

  • Clearance in Piston (Service)

0.025 mm (Maximum)

0.0010 in (Maximum)

  • Diameter

23.545-23.548 mm

0.9270-0.9270 in

  • Fit in Connecting Rod

0.021-0.040 mm (Interference)

0.0008-0.0016 in (Interference)

Piston Rings (End Gap Measured in Cylinder Bore)

  • Piston Compression Ring Gap (Production-Top Groove)

0.25-0.40 mm

0.010-0.016 in

  • Piston Compression Ring Gap (Production-2nd Groove)

0.46-0.66 mm (Maximum)

0.018-0.026 in (Maximum)

  • Piston Compression Ring Gap (Service-Top Groove)

0.5 mm (Maximum)

0.19 in (Maximum)

  • Piston Compression Ring Gap (Service-2nd Groove)

0.8 mm (Maximum)

0.31 in (Maximum)

  • Piston Compression Ring Groove Clearance (Production-Top Groove)

0.030-0.070 mm

0.0012-0.0027 in

  • Piston Compression Ring Groove Clearance (Production-2nd Groove)

0.040-0.080 mm

0.0015-0.0031 in

  • Piston Compression Ring Groove Clearance (Service)

0.085 mm (Maximum)

0.0033 in (Maximum)

  • Piston Oil Ring Gap (Production)

0.25-0.76 mm

0.010-0.029 in

  • Piston Oil Ring Gap (Service)

0.90 mm (Maximum)

0.035 in (Maximum)

  • Piston Oil Ring Groove Clearance (Production)

0.046-0.096 mm

0.0018-0.0037 in

  • Piston Oil Ring Groove Clearance (Service)

0.10 mm (Maximum)

0.0039 in (Maximum)

Valve System

  • Valve Face Angle

45 degrees

  • Valve Head Edge Margin

0.79 mm (Minimum)

0.031 in (Minimum)

  • Valve Lash

Net Lash--No Adjustment

  • Valve Lift (Exhaust) (L35)

10.879 mm

0.4280 in

  • Valve Lift (Exhaust) (LF6)

9.887 mm

0.3890 in

  • Valve Lift (Intake) (L35)

10.527 mm

0.4140 in

  • Valve Lift (Intake) (LF6)

10.215 mm

0.4020 in

  • Valve Lifter

Hydraulic Roller

  • Valve Rocker Arm Ratio

1.5:1

  • Valve Seat Angle

46 degrees

  • Valve Seat Runout

0.05 mm (Maximum)

0.002 in (Maximum)

  • Valve Seat Width (Exhaust)

1.575-2.362 mm

0.065-0.098 in

  • Valve Seat Width (Intake)

0.89-1.52 mm

0.035-0.060 in

  • Valve Spring Free Length

51.3 mm

2.02 in

  • Valve Spring Installed Height (Exhaust)

42.92-43.43 mm

1.670-1.700 in

  • Valve Spring Installed Height (Intake)

42.92-43.43 mm

1.670-1.700 in

  • Valve Spring Pressure (Closed)

338-374 N at 43.2 mm

76-84 lb at 1.70 in

  • Valve Spring Pressure (Open)

832-903 N at 32.3 mm

187-203 lb at 1.27 in

  • Valve Stem Clearance (Exhaust-Production)

0.025-0.069 mm

0.0010-0.0027 in

  • Valve Stem Clearance (Exhaust-Service)

0.025-0.094 mm

0.0010-0.0037 in

  • Valve Stem Clearance (Intake-Production)

0.025-0.069 mm

0.0010-0.0027 in

  • Valve Stem Clearance (Intake-Service)

0.025-0.094 mm

0.0010-0.0037 in

  • Valve Stem Oil Seal Installed Height (Measured from the Top of the Large Diameter Valve Guide Bevel to the Bottom of the Valve Stem Oil Seal)

1-2 mm

0.03937-0.07874 in